Places We Protect

Mary Macdonald Preserve at Horseshoe Harbor


Water between two large rock formations, covered in lichen and other plants, along the shore of Lake Superior in the Keweenaw Peninsula of Michigan.
Horseshoe Harbor Sunrise hits the bedrock at Mary Macdonald Preserve at Horseshoe Harbor. © TNC

Please note, access to the preserve may be limited on the dates below due to upcoming events.

August 8-9, 15-16 and 29-30; September 12-13; September 30-October 1



At the tip of Michigan’s Upper Peninsula, stunted shrubs and trees cling to ancient bedrock created by Lake Superior’s fierce winds. Since it was originally established in 1982, the Mary Macdonald Preserve has grown to encompass 1,200 acres, including five miles of Lake Superior shoreline. While the rugged bedrock beach here supports only the toughest of plants such as lichen, the preserve is home to 11 threatened or rare species.

Along the shoreline, a rocky ridge creates a barrier for inland species and slower-growing plants. Just inland from the rock beaches, forest thrives in this cool, moist climate. Balsam fir, white cedar, white spruce and white birch provide habitat for the black bear, snowshoe hare, peregrine falcon, ruffed grouse, golden-crown kinglet, black-throated green warbler and yellow-rumped warbler. 




Hiking, snowshoeing, birdwatching, swimming and deer hunting (by permit)


1,261 acres

Explore our work in this region

Legacy of the Keweenaw

The Mary Macdonald Preserve at Horseshoe Harbor is in the Keweenaw Peninsula, an area cherished by residents and visitors alike. It is also the heart of one of the most unfragmented and climate-resilient areas in the northern Great Lakes region.

Explore the Keweenaw
Waves crash into boulders along the rocky shore of the Mary Macdonald Preserve at Horseshoe Harbor in the Keweenaw Peninsula.
The Nature Conservancy preserve sign at Mary Macdonald Preserve at Horseshoe Harbor in the Keweenaw Peninsula.
The sun sets over Lake Superior and reflects in the water at the Mary Macdonald Preserve at Horseshoe Harbor in the Keweenaw Peninsula.
A mink frog rests in the shallow water at Mary Macdonald Preserve at Horseshoe Harbor in the Keweenaw Peninsula.
Brightly colored lichen on a rock at Horseshoe Harbor on the Keweenaw Peninsula in Michigan.

Preserve Audio Tour

Our guided audio tours include stories, fun facts, historical notes and natural sounds to help deepen your connection to the world. You can access the tour from the comfort of your home, or on site as you hike.

The Mary Macdonald Preserve at Horseshoe Harbor captures the beauty—and ruggedness—of the Keweenaw Peninsula’s northern shoreline. Here, ancient geological forces and the power of wind and water have shaped a unique coastal landscape of bedrock ridges, red rock beaches and boreal forests that draws many migratory birds—and human visitors—to its shores. 


Spotlight on the Mary Macdonald Preserve

Spotlight on Nature (3:03) The Mary Macdonald Preserve at Horseshoe Harbor, on the northern shore of the peninsula, is one of our most popular preserves with visitors.

Plan Your Visit

  • When to Visit

    This preserve is open year round. However, late summer and early fall are the best times to visit to fully enjoy the beauty of the Keweenaw Peninsula without the irritation of the biting insects that come out in the early summer. 

    Please note, access to the preserve may be limited on the following dates due to upcoming events: August 8-9, 15-16 and 29-30; September 12-13; September 30-October 1

  • What to Bring

    Hiking boots are recommended for walking the trails and shoreline of this preserve. If you want to visit during the early summer months bring insect repellant to protect against biting insects.

  • Permitted Activities
    • Hiking, skiing, and snowshoeing
    • Bird watching, nature study and photography
    • Swimming
    • Geocaching
    • Kayaks and canoes are permitted on Lake Superior. Vessels must be carried from the parking area.
    • Research projects and educational studies with approved permit
    • Hunting with a Conservancy-issued permit for whitetail deer
  • Prohibited Activities
    • No rock climbing and rappelling
    • No motorized and non-motorized vehicles
    • No building of new trails
    • No pets
    • No hunting or trapping without a Conservancy-issued permit
    • No removal of plants or animals (alive or dead)
    • No removal of rocks, water or other non-organic materials
    • No camping, bonfires, fireworks or other fires
    • No firewood collecting
    • No littering
  • Hunting

    The Nature Conservancy allows hunting for white-tail deer on this preserve to reduce threats too many deer can pose to the other plants and animals that live here. All hunters are required to receive a permit from the Conservancy as well as a Michigan deer hunting license. Additionally, hunters must report any deer taken from the preserve.

  • Questions

    Have questions about the preserve? Contact Shaun Howard, TNC protected lands project manager in Michigan.

Keep Exploring

From shifting sand dunes to granite bald mountains, explore over 35 preserves and reserves spread across the state of Michigan.

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Find More Places We Protect

The Nature Conservancy owns nearly 1,500 preserves covering more than 2.5 million acres across all 50 states. These lands protect wildlife and natural systems, serve as living laboratories for innovative science and connect people to the natural world.

See the Complete Map

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